Dual signal alarm device responsive to high frequency signals superimposed on a power line



R. H. VOIGT ETAL Sept. 8, 1964 4 3,148,365

' DUAL SIGNAL ALARM DEVICE RESPONSIVE TO HIGH FREQUENCY SIGNALS SUPERIMPOSED ON A POWER LINE Filed March 12, 1962 F fiober-f BY 11/17/1220: 6. Wewbeg 3,148,365 DUAL SIGNAL ALARM DEVICE RESPONSIVE TO HIGH FREQUENCY SIGNALS SUPERKMPOSED ON A PGWER LlNE Robert H. Voigt and William C. Newberg, Milford, Mich,

assignors to Aseco, Incorporated, Milford, Mich, a corporation of Michigan Filed Mar. 12, 1962, Ser. No. 179,058 9 Claims. (Cl. 34tl310) This invention relates to electrical control circuits for producing a plurality of audibly distinguishable alarms and more particularly to a multiple purpose alarm device which may be actuated from some central point to warn of impending danger and which will also produce an audibly distinguishable alarm in the event of a fire within the immediate vicinity of the device.

A copending application for NEAR Receivers, Serial No. 169,463, filed January 29, 1962, discloses a receiving instrument designed to be used as a component of the National Emergency Alarm Repeater (NEAR) system. This system developed by the Office of Civil Defense Mobilization provides for the use of existing power lines to provide a means of warning the population in the event of an enemy attack. Generating equipment will transmit a signal in the form of a short burst of 240 cycles per second frequency superimposed on the 60 cycle power normally being transmitted through the power lines. A receiver unit which is plugged into an ordinary wall receptacle will actuate a buzzer or a bell upon receipt of the signal.

The present invention discloses an improved receiving component for the NEAR system having means which will also produce an alarm signal in the event of a fire which is readily identifiable from the base NEAR alarm signal.

It is an object of the present invention to produce an effective multipurpose alarm system by providing means producing audibly distinguishable alarm signals.

It is another object of the present invention to provide an alarm device which will produce an interrupted audible signal by providing an alarm switch and means upon being energized alternately opening and closing said switch.

It is another object of the present invention to produce a combination NEAR receiving component and fire alarm device by providing means producing one alarm signal upon actuation by the NEAR system and producing another and different alarm signal in the event of a fire.

It is still another object of the present invention to produce an improved fire alarm system by providing an alarm device which will either produce an alarm signal upon being electrically actuated from some distant point or will automatically produce an alarm signal in the event of a fire in the vicinity of the device.

Still further objects and advantages will readily occur to one skilled in the art upon reference to the following drawings in which like reference characters refer to like parts throughout the several views and in which FIG. 1 is a diagrammatic view of a preferred embodiment of the present invention, and

FIG. 2 is a diagrammatic view of another preferred embodiment of the present invention.

Now referring to the drawings for a more complete understanding of the present invention, PEG. 1 illustrates 3,148,355 Patented Sept. 8., 1964 diagrammatically a preferred alarm device as comprising an input line plug 1 adapted for insertion into an ordinary A.C. current household wall receptacle or the like (not shown) and having prongs 2 and 3. The prong 2 is connected to a rectifier 4 which rectifies the AC. current (preferably 110 volt 6O cycle current) to a pulsating D.C. current.

A neon lamp circuit indicated generally at 5 and a resonance circuit indicated at 6 are each connected across the plug 1 as shown. The neon lamp circuit 5 preferably comprises voltage divider resistors '7 and 8 with a neon lamp 9 connected as shown. Thus when the plug 1 is inserted into a wall receptacle the lamp 9 will remain lit indicating that the alarm device is operable.

The resonance circuit 6 includes a capacitor 1t} and an electromagnetic coil 11 which forms a series tuned LC circuit. The capacitive resistance of the capacitor 1% is approximately the same as the inductive reactance of the electromagnetic coil 11 at a predetermined signal frequency. Thus when this predetermined signal frequency is superimposed on the ordinary power lines, the reactances cancel one another and the circuit is resonant at that frequency.

A resonance relay 12 is disposed within the magnetic field of the electromagnetic coil 11 and preferably comprises a normally open switch 14 having one contact 14A carried adjacent a resonant reed 15 and the other contact 14B carried on a leaf 14C pivotally mounted on a hair spring 14D. The contact 14A is connected to the DC. side of the rectifier 4.

The leaf 140 is connected with an electromagnetic coil 26. An armature 27 is disposed closely adjacent the electromagnetic coil 26 and is operably connected to an axially movable pin 28. The pin 28 is preferably spring loaded in the direction of the arrow to hold the diaphragm 29A of a time delay fluid cell 29 in a normally closed or exhausted position.

A normally open switch 31 is disposed between the fluid cell 29 and the armature 27 and comprises normally spaced contact members 32, 33 and 34, each carried On the end of spring leaf members 35, 36 and 37 respectively. The leaf 35 carrying the contact 32 is connected with the V DC. side of the rectifier 4. The leaf 36 carrying the contact 33 is connected with the electromagnetic coil 11. A clapper 39 is positioned within the magnetic field of the coil 11.

The DC side of the rectifier 4 is connected to a normally open switch 49. The switch til includes a bimetal heat responsive leaf 41 pivotally carried as at 42 and a contact 43 connected to the electromagnetic coil 11.

A closed interrupter circuit .4- is provided with a low voltage winding 45 disposed within the magnetic field of the coil 11 and a bimetal face portion 46. A pin 47 is movable upon deformation of the face portion 46 to urge the leaf 41 out of contact with the contact 43.

In operation a predetermined alarm actuating signal may be superimposed upon the current normally passing through the power lines. This actuation signal will pass through the resonance circuit 6 causing the resonant reed 15 to vibrate causing the switch 14 to close. The hair spring 14D will be induced to vibrate the leaf MC as the reed 15 vibrates, thus producing a non-interrupting contact through the switch 14-. This energizes the electromagnet 26 causing the armature 27 and pin 28 to move setting into operation the slow expansion of the fluid cell diaphragm substantially as disclosed in the aforementioned co-pending application. The contacts 32333-t engage and the armature 2.7 is held in position since the contact 34 is connected to the electromagnetic coil 2.6. The leaf member 32 is of a bi-metal construction and a heater winding 48 is disposed to be energized by the closing of the switch 31 and is operable to warp the leaf member 3'7 and thus open the switch after a predetermined time interval has elapsed.

A flow of current passes through the closed switch SI to excite the electromagnetic coil 11. The coil Eli excites the clapper 3? and an audible alarm is sounded. The alarm continues until the heater winding 48 heats the bimetal leaf 3'7 causing it to warp and the contacts 32-34 to break, which in turn de-energizes the coil 26 and causes the contacts 33-34 to break.

I In the event of a fire in the vicinity of the device, the leaf 41 will warp to engage the contact 43 thus energizing the coil 11 and the clapper 39. The magnetic force produced by the coil Ill will induce a current to flow through the interrupter circuit 44. The face portion 46 is heated by the current and warps to move the pin 47 toward the leaf 41 and thus momentarily opens the switch 40. As the face portion 46 cools, the leaf 4-1 will again move to engage the contact 43. Thus an interrupted audible alarm will be sounded which is readily distinguishable from the continuous signal actuated NEAR system alarms. It is apparent that to produce this operation it is necessary to construct the leaf 41 of a bimetal construction which responds to a much lower heat than the face portion 46.

FIG. 2 shows another preferred embodiment of the present invention which includes a second resonance relay ltld disposed within the magnetic field of the coil ill and comprises a normally open switch 114 having one contact 114A fixed to a resonant reed 115 which is pivotally mounted at one end at 115A, with the contact 114A being connected to the DC. side of the rectifier 4. The contact 114B is connected to a coil d. An armature 51 is disposed closely adjacent the coil Stl and is operable upon the coil 50 being energized to move a pin 52 axially against the leaf 41, urging it to engage the contact 43.

The interruptor circuit 44 will operate as in the embodiment of FIG. 1 to produce an interrupted audible alarm.

In operation the resonant reed 115 is tuned to a signal frequency different than the signal frequency of the reed I5. Imposing this signal on the normal power lines will enable a fire alarm signal to be sounded from a single central point. The embodiment as disclosed in FIG. 2 then will function as a NEAR receiving component, a fire detecting alarm device and a fire alarm transmitting device.

It is apparent that other changes and modifications may be made in the present invention without departing from the spirit or the scope of the appended claims.

We claim:

1. In an alarm system having a source of electrical power and means selectively imposing a predetermined actuation signal thereon, a dual signal alarm device comprising,

(a) a first alarm circuit including a switch and means producing an audible alarm upon actuation of said switch,

(b) means actuating said switch and including an energizing circuit,

(c) said energizing circuit being operable to actuate said switch upon receipt of said predetermined actuation signal,

(d) a second alarm circuit including a second switch and means producing an alarm audibly distinguishable from said first mentioned alarm upon actuation of said second switch,

(e) means actuating said second mentioned switch and 3 including an energizing circuit and a heat responsive element,

(f) said heat responsive element being operable to actuate said second mentioned switch upon being heated to a predetermined temperature.

2. The device as defined in claim 1 and including,

(a) means producing a non-interrupted audible alarm upon actuation of said first mentioned switch, and

(b) means producing an interrupted alarm upon actuation of said second mentioned switch;

3. The device as defined inclaim 1 and including means connected with and operable to actuate said second mentioned switch upon receipt of a predetermined actuation signal different from the actuation signal which actuates said first mentioned switch.

4. In an alarm system having a source of electrical power and means selectively imposing a selected range of different predetermined actuation signals thereon, an alarm device comprising (a) a first alarm circuit including a switch and means producing an audible alarm upon actuation of said switch,

(1;) a resonance circuit including a capacitor tuned to the frequency of a selected actuation signal within the range of signals which may be imposed upon said electrical power and an electromagnetic coil,

(0) a first resonance relay having a switch disposed closely adjacent said electromagnetic coil and being actuated upon receipt of said actuation signal by said capacitor,

(d) means energized by the actuation of said relay switch and being operable to actuate said first alarm circuit,

(e) a second alarm circuit including a switch and means producing an alarm audibly distinguishable from said first mentioned alarm upon actuation of said second mentioned switch,

(f) means actuating said second mentioned switch and including an energizing circuit and a heat responsive element,

(g) said heat responsive element being operable to actuate said second switch upon being heated to a predetermined temperature.

5. The device as defined in claim 4 and including ,(a) a third alarm circuit connected to said second mentioned switch,

- (b) a second resonance relay having a switch closely adjacent said electromagnetic coil and being actuated upon receipt of a predetermined actuation signal different than the signal actuating said first resonance relay,

(0) means energized by the actuation of said second relay switch and being operable to actuate said second alarm circuit.

6. The device as defined in claim 5 and in which (a) said first alarm circuit being operable to produce a non-interrupted alarm signal of a predetermined interval, and

(b) said second alarm switch being operable to produce an alarm upon being actuated to a closed position, and

(0) means energized by said second mentioned energizing circuit and being operable to open and close said second alarm switch at regular intervals whereby an interrupted audible alarm is produced.

7. In an alarm system having a source of electrical power and means selectively imposing at least two different predetermined actuation signals thereon, a dual signal alarm device comprising,

(a) a first alarm circuit including a switch and means producing an audible alarm upon actuation of said switch,

(b) means actuating said switch and including an energizing circuit,

(C) said energizing circuit being operable to actuate sponsive means operable to actuate said second switch upon rise of temperature in the vicinity of said device.

9. The device as defined in claim 7 and including (a) means periodically interrupting actuation of said second switch.

References Cited in the file of this patent UNITED STATES PATENTS 2,339,025 Matthews Ian. 11, 1944 2,388,350 Deal Nov. 6, 1945 2,580,539 Goodwin Ian. 1, 1952 3,021,520 Weber Feb. 13, 1962 

1. IN AN ALARM SYSTEM HAVING A SOURCE OF ELECTRICAL POWER AND MEANS SELECTIVELY IMPOSING A PREDETERMINED ACTUATION SIGNAL THEREON, A DUAL SIGNAL ALARM DEVICE COMPRISING, (A) A FIRST ALARM CIRCUIT INCLUDING A SWITCH AND MEANS PRODUCING AN AUDIBLE ALARM UPON ACTUATION OF SAID SWITCH, (B) MEANS ACTUATING SAID SWITCH AND INCLUDING AN ENERGIZING CIRCUIT, (C) SAID ENERGIZING CIRCUIT BEING OPERABLE TO ACTUATE SAID SWITCH UPON RECEIPT OF SAID PREDETERMINED ACTUATION SIGNAL, (D) A SECOND ALARM CIRCUIT INCLUDING A SECOND SWITCH AND MEANS PRODUCING AN ALARM AUDIBLY DISTINGUISHABLE FROM SAID FIRST MENTIONED ALARM UPON ACTUATION OF SAID SECOND SWITCH, (E) MEANS ACTUATING SAID SECOND MENTIONED SWITCH AND INCLUDING AN ENERGIZING CIRCUIT AND A HEAT RESPONSIVE ELEMENT, (F) SAID HEAT RESPONSIVE ELEMENT BEING OPERABLE TO ACTUATE SAID SECOND MENTIONED SWITCH UPON BEING HEATED TO A PREDETERMINED TEMPERATURE. 